Let us assume the number of children attending the movie = x Let us also assume the number of adults attending the movie = y Cost of admission for a children in the movie = $8 Cost of admission of an adult in the movie = $12 Number of people going to the movie on a certain day = 3200 Total amount collected from the movie theater = $33040 Then x + y = 3200 And 8x + 12y = 33040 2x + 3y = 8260 Let us first take the equation x + y = 3200 x = 3200 - y Now we will put the value of x in the equation 2x + 3y = 8260 2(3200 - y) + 3y = 8260 6400 - 2y + 3y = 8260 y = 8260 - 6400 = 1860 Now we will put the value of y from the above deduction in the equation x + y = 3200 x + 1860 = 3200 x = 3200 - 1860 = 1340 So the number of children going to the movie theater is 1340 and the number of adults going to the movie theater is 1860.
To answer this you could write the first rate that is given (12 plants: 1.5 hours in fraction form and make it equivalent to a second rate of x: 1 hour. X represents the number of plants in an hour.
You can use cross products to solve for x. Please see the attached picture for the steps. The answer is 8 plants.
